Page 44 - Occupational Health & Safety, January/February 2020

RESPIRATORY PROTECTION
Seven Challenges of Implementing Medical Surveillance under OSHA’s New Respirable Silica Standard
OSHA’s silica standard addresses many aspects of workplace protection, including having a written plan, environmental monitoring, housekeeping, training and use of respirators.
BY KENT PETERSON
OSHA’s newest major health protection stan- dard (29 CFR 1926.1153) addresses respira- ble crystalline silica in construction, general industry, maritime, and hydraulic fractur-
ing.1 Effective implementation dates range from June 2018 to June 2020, so health and safety professionals are actively designing and refining silica programs.
The silica standard addresses many aspects of workplace protection, including having a written plan, environmental monitoring, housekeeping, training and use of respirators.
Silica Exposure
The OSHA Directorate of Standards and Guidance estimates that 1.8 million workers in construction are at risk of overexposed to silica, plus another 320,000 workers in general industry. These workers represent a wide range of occupations and industrial sectors (See Table 1).2
Adverse Effects of Respirable
Silica Exposure
Adverse effects of silica exposure are largely pulmo- nary. Most common is chronic obstructive pulmo- nary disease (COPD), such as chronic bronchitis and emphysema. Also common is lung cancer. The Inter- national Association for Research on Cancer (IARC) classifies silica in Group 1—a proven carcinogen to humans.3 Lung infections are triggered by the in- flammatory effects of fine silica dust, resulting in atypical fungus infections of the lungs and activation of latent tuberculosis (TB), called “consumption” in Ramazzini’s era.
Most common symptoms are shortness of breath, cough (usually dry, but can produce sputum or blood), pleuritic chest pain on deep inspiration, and constitutional symptoms from secondary diseases such as fever from TB, or loss of appetite and weight loss from cancer. Additionally, silica exposure is as- sociated with kidney disease and renal failure, as well as various kinds of autoimmune disorders, including lupus erythematosis.
Three kinds of silicosis reflect varying duration of exposure and resultant effects. Most common is chronic silicosis, a slow, but steadily progressive con- dition found among workers with more than 10 years of exposure. Accelerated silicosis comes from exces-
sive exposure over five to 10 years. Since 2000, an epi- demic of progressive massive pulmonary fibrosis has emerged among coal miners who must increasingly blast through underground rock to reveal lower con- centrations of coal in smaller layer.
Short-term exposure to overwhelming amounts of respirable silica can cause acute silicosis. An example is severe lung disease among three people working for only a year as countertop cutters, in environments with neither proper ventilation nor respiratory protection.
Silica Standard Breaks New Ground
The respirable silica standard breaks new ground in many areas. One highlight is the referral of workers with significant pulmonary disease (based on exami- nation and/or chest x-ray B reading) to a specialist in occupational medicine or pulmonary disease. It also is the first to require written employee authorization to communicate certain results to the employer.
The silica standard creates profound differences in the information provided in written medical opinions for the employee and the employer (See Table 2).
Appendix B, Medical Surveillance Guidelines, outlines silica’s health effects and details many aspects of the surveillance exam and medical report require- ments.4 This appendix is a model of excellence that OSHA should emulate in updating old standards and issuing new ones.
Medical Surveillance Requirements
Workers above the exposure trigger (action level above the PEL of 50 mcg/cu M or Action Levels of 25 mcg/cu M) or those required to wear a respirator 30 or more days per year must be offered medical sur- veillance examinations every three years. The exams include several components:
■ Medical and work history
■ Pulmonary Function Testing, including FVC, FEV1, FEV1/FVC ratio (by a NIOSH-certi- fied technician)
■ Chest X-ray (PA view) with ILO interpreta- tion of small opacities, ground glass appearance (by a NIOSH-certified B-reader)
■ TB Test – initial exam only (skin or blood test)
■ Physical Exam by an examining physician or other licensed health care provider (PLHCP)
40 Occupational Health & Safety | JANUARY/FEBRUARY 2020
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